Aldehydes, Ketones, and Carboxylic Acids – MCQs (NEET Style)
Q1. The functional group of aldehydes is:
A. –COOH
B. –CHO
C. –OH
D. –C=O
Q2. The functional group of ketones is:
A. –CHO
B. –COOH
C. –C=O
D. –OH
Q3. The IUPAC name of CH₃CH₂CHO is:
A. Propanal
B. Propanone
C. Butanal
D. Acetone
Q4. The IUPAC name of CH₃COCH₃ is:
A. Propanal
B. Propanone
C. Butanone
D. Acetaldehyde
Q5. Which of the following has higher boiling point?
A. Aldehyde
B. Ketone
C. Alcohol
D. Ether
Q6. Aldehydes can be prepared by:
A. Oxidation of primary alcohols
B. Ozonolysis of alkenes
C. Rosenmund reduction of acid chlorides
D. All of the above
Q7. Ketones can be prepared by:
A. Oxidation of secondary alcohols
B. Friedel-Crafts acylation
C. Ozonolysis of alkenes
D. All of the above
Q8. Carboxylic acids can be prepared by:
A. Oxidation of aldehydes
B. Hydrolysis of nitriles
C. Carbonation of Grignard reagents
D. All of the above
Q9. Which reagent oxidizes aldehydes to carboxylic acids?
A. KMnO₄
B. Tollens’ reagent
C. Fehling’s solution
D. All of the above
Q10. Aldehydes react with:
A. HCN → Cyanohydrin
B. NH₂OH → Oxime
C. 2,4-DNP → 2,4-DNP derivative
D. All of the above
Q11. Ketones react with:
A. HCN → Cyanohydrin
B. NH₂OH → Oxime
C. 2,4-DNP → 2,4-DNP derivative
D. All of the above
Q12. Aldehyde can be distinguished from ketone by:
A. Tollen’s test
B. Fehling’s test
C. Both A and B
D. 2,4-DNP test
Q13. Cannizzaro reaction occurs with:
A. Aldehydes without α-H
B. Ketones
C. Carboxylic acids
D. Alcohols
Q14. Aldol condensation occurs with:
A. Aldehydes having α-H
B. Ketones having α-H
C. Both A and B
D. Alcohols
Q15. CH₃CHO + NaBH₄ →
A. CH₃CH₂OH
B. CH₃CHOHCH₃
C. CH₃COOH
D. CH₃CH₂CH₃
Q16. CH₃COCH₃ + NaBH₄ →
A. CH₃CHOHCH₃
B. CH₃CH₂OH
C. CH₃COOH
D. CH₃CH₂CH₃
Q17. Aldehydes are generally:
A. More reactive than ketones
B. Less reactive than ketones
C. Equally reactive
D. Non-reactive
Q18. Ketones are generally:
A. Less reactive than aldehydes
B. More reactive than aldehydes
C. Non-reactive
D. Only acidic
Q19. Carboxylic acids + Alcohol →
A. Ester
B. Ketone
C. Aldehyde
D. Ether
Q20. Carboxylic acids react with:
A. PCl₅ → Acyl chloride
B. SOCl₂ → Acyl chloride
C. Both A and B
D. Alcohol only
Q21. Aldehydes + Ag(NH₃)₂⁺ (Tollen’s) →
A. Ag mirror
B. No reaction
C. Precipitate
D. Aldol
Q22. Aldehydes + Fehling’s solution →
A. Red precipitate (Cu₂O)
B. No reaction
C. Ketone
D. Ester
Q23. Oxidation of aldehydes gives:
A. Carboxylic acids
B. Ketones
C. Alcohols
D. Ethers
Q24. Reduction of aldehydes gives:
A. Primary alcohols
B. Secondary alcohols
C. Ketones
D. Carboxylic acids
Q25. Reduction of ketones gives:
A. Secondary alcohols
B. Primary alcohols
C. Aldehydes
D. Carboxylic acids
Q26. Relative reactivity of aldehydes vs ketones toward nucleophilic addition:
A. Aldehyde > Ketone
B. Ketone > Aldehyde
C. Equal
D. Non-reactive
Q27. Carboxylic acids + NaHCO₃ →
A. CO₂ evolution
B. No reaction
C. Precipitate
D. Ether
Q28. Carboxylic acids + LiAlH₄ →
A. Primary alcohol
B. Secondary alcohol
C. Ketone
D. Aldehyde
Q29. Aldehydes + 2,4-DNP →
A. Orange/red precipitate
B. Silver mirror
C. Gas evolution
D. No reaction
Q30. Ketones + 2,4-DNP →
A. Orange/red precipitate
B. Silver mirror
C. Gas evolution
D. No reaction
Q31. Decarboxylation of sodium salts of carboxylic acids with soda lime gives:
A. Alkane
B. Alkene
C. Alcohol
D. Ether
Q32. Aldehydes + I₂ + NaOH →
A. Yellow precipitate (CHI₃)
B. No reaction
C. Red precipitate
D. Ether
Q33. Ketones + I₂ + NaOH →
A. Yellow precipitate if methyl ketone (iodoform test)
B. No reaction
C. Red precipitate
D. Ether
Q34. Which reagent converts acid to acyl chloride?
A. SOCl₂
B. PCl₅
C. Both A and B
D. NaBH₄
Q35. Friedel-Crafts acylation gives:
A. Aryl ketone
B. Aldehyde
C. Alcohol
D. Ether
Q36. Aldehydes react with NH₂OH →
A. Oximes
B. Hydrazones
C. Semicarbazones
D. All of the above
Q37. Aldehydes react with hydrazine derivatives to give:
A. Hydrazones
B. Cyanohydrin
C. Ester
D. Ether
Q38. Carboxylic acids + PCl₅ →
A. Acyl chloride + POCl₃ + HCl
B. Alcohol
C. Ether
D. Ketone
Q39. Oxidation of secondary alcohol →
A. Ketone
B. Aldehyde
C. Carboxylic acid
D. Ether
Q40. Oxidation of primary alcohol →
A. Aldehyde → Carboxylic acid
B. Ketone
C. Ether
D. Alcohol
Q41. Aldehyde + NaHSO₃ →
A. Addition compound (bisulfite)
B. No reaction
C. Ester
D. Ether
Q42. Ketone + NaHSO₃ →
A. Addition compound (bisulfite)
B. No reaction
C. Ester
D. Ether
Q43. Carboxylic acids + P₂O₅ →
A. Anhydride
B. Ester
C. Ketone
D. Alcohol
Q44. Aldehydes undergo:
A. Nucleophilic addition
B. Oxidation
C. Reduction
D. All of the above
Q45. Ketones undergo:
A. Nucleophilic addition
B. Oxidation (only weak)
C. Reduction
D. All of the above
Q46. Aldehydes + NaBH₄ →
A. Primary alcohol
B. Secondary alcohol
C. Ketone
D. Ether
Q47. Ketones + NaBH₄ →
A. Secondary alcohol
B. Primary alcohol
C. Carboxylic acid
D. Ether
Q48. Oxidation of aldehyde with Tollen’s reagent →
A. Carboxylic acid + Silver mirror
B. No reaction
C. Ketone
D. Alcohol
Q49. Which is more reactive toward nucleophilic addition?
A. Aldehyde > Ketone
B. Ketone > Aldehyde
C. Equal
D. Non-reactive
Q50. Carboxylic acids have:
A. Hydrogen bonding → High boiling point
B. Acidic nature
C. Solubility in water (smaller acids)
D. All of the above
Q1. B – Aldehydes have –CHO functional group.
Q2. C – Ketones have C=O functional group within the carbon chain.
Q3. A – CH₃CH₂CHO is Propanal.
Q4. B – CH₃COCH₃ is Propanone (acetone).
Q5. C – Alcohols > Aldehydes/Ketones due to hydrogen bonding.
Q6. D – Aldehydes can be prepared by all listed methods.
Q7. D – Ketones can be prepared by oxidation of secondary alcohols, Friedel-Crafts acylation, ozonolysis.
Q8. D – Carboxylic acids can be prepared by oxidation, nitrile hydrolysis, carbonation of Grignard.
Q9. D – Aldehydes oxidize to acids with KMnO₄, Tollens’, or Fehling’s.
Q10. D – Aldehydes react with HCN, NH₂OH, 2,4-DNP.
Q11. D – Ketones also react with HCN, NH₂OH, 2,4-DNP.
Q12. C – Aldehydes can be distinguished from ketones by Tollen’s/Fehling’s test.
Q13. A – Cannizzaro occurs with aldehydes having no α-H.
Q14. C – Aldol condensation occurs with aldehydes or ketones having α-H.
Q15. A – CH₃CHO + NaBH₄ → CH₃CH₂OH (primary alcohol).
Q16. A – CH₃COCH₃ + NaBH₄ → CH₃CHOHCH₃ (secondary alcohol).
Q17. A – Aldehydes are generally more reactive than ketones.
Q18. A – Ketones are less reactive than aldehydes.
Q19. A – Carboxylic acid + alcohol → Ester.
Q20. C – Acyl chlorides can be prepared using SOCl₂ or PCl₅.
Q21. A – Aldehydes + Tollen’s reagent → Silver mirror.
Q22. A – Aldehydes + Fehling’s → Red Cu₂O precipitate.
Q23. A – Oxidation of aldehydes → Carboxylic acids.
Q24. A – Reduction of aldehydes → Primary alcohols.
Q25. A – Reduction of ketones → Secondary alcohols.
Q26. A – Aldehydes are more reactive toward nucleophilic addition.
Q27. A – Carboxylic acids + NaHCO₃ → CO₂ evolution.
Q28. A – Carboxylic acids + LiAlH₄ → Primary alcohols.
Q29. A – Aldehydes + 2,4-DNP → Orange/red precipitate.
Q30. A – Ketones + 2,4-DNP → Orange/red precipitate.
Q31. A – Decarboxylation of sodium salts → Alkane.
Q32. A – Aldehydes + I₂/NaOH → Yellow precipitate (iodoform test for CH₃CHO).
Q33. A – Ketones with methyl group (CH₃–CO–R) give iodoform.
Q34. C – Acid chlorides prepared using SOCl₂ or PCl₅.
Q35. A – Friedel-Crafts acylation → Aryl ketone.
Q36. D – Aldehydes react with NH₂OH, hydrazine, semicarbazide → Oximes, hydrazones, semicarbazones.
Q37. A – Hydrazine derivatives form hydrazones.
Q38. A – Carboxylic acids + PCl₅ → Acyl chloride + POCl₃ + HCl.
Q39. A – Oxidation of secondary alcohol → Ketone.
Q40. A – Oxidation of primary alcohol → Aldehyde → Carboxylic acid.
Q41. A – Aldehyde + NaHSO₃ → Bisulfite addition compound.
Q42. A – Ketone + NaHSO₃ → Bisulfite addition compound.
Q43. A – P₂O₅ converts carboxylic acids to anhydrides.
Q44. D – Aldehydes undergo nucleophilic addition, oxidation, reduction.
Q45. D – Ketones undergo nucleophilic addition, reduction; oxidation is slow.
Q46. A – Aldehydes + NaBH₄ → Primary alcohol.
Q47. A – Ketones + NaBH₄ → Secondary alcohol.
Q48. A – Aldehyde oxidation with Tollen’s → Silver mirror.
Q49. A – Aldehydes > Ketones in nucleophilic addition reactivity.
Q50. D – Carboxylic acids have hydrogen bonding, acidity, and solubility (small acids).